Preparation of sage extracts (Salvia officinalis L.) and determination of polyphenolic compounds

Ekstrakti kadulje zbog svog visokog udjela polifenolnih spojeva imaju potencijal primjene prirodnih inhibitora rasta oomicetnih patogena. Stoga, istraživan je utjecaj različitih vrsta otapala: voda, etanol (96%), etanol-voda (1:1), aceton (100%), aceton-voda (1:1), metanol (100%), metanol-voda (1:1), etanol-metanol-aceton (1:1:1) i etanol-metanol-aceton-voda (1:1:1:1) na ekstrakciju polifenolnih spojeva samonikle kadulje (Salvia officinalis L). Provedena je ekstrakcija refluksiranjem pri temperaturi ključanja otapala kroz 1 h i maceracija kroz 72 h te su spektrofotometrijskom metodom (UV/VIS) određeni maseni udjeli ukupnih fenola, hidroksicimetnih kiselina, ukupnih flavonoida i flavonola. Neovisno o primijenjenom postupku ekstrakcije, kombinacijom otapala etanol-metanol-aceton-voda ekstrahiran je veći maseni udio ukupnih fenola (134,87 mg/g), hidroksicimetnih kiselina (66,08 mg/g) i flavonola (49,36 mg/g), dok se metanol pokazao najboljim za izolaciju flavonoida. Na temelju dobivenih rezultata može se zaključiti da se bolji učinak ekstrakcije polifenolnih spojeva postiže kombinacijom otapala, te dodatkom vode u otapalo, nego primjenom čistog otapala.Sage extract due to its high proportion of polyphenolic compounds has the potential to be used as a natural inhibitor for the growth of oomycete pathogens. Therefore, the influence of different types of solvents on the extraction of polyphenolic compounds of wild sage (Salvia officinalis L.) was investigated. Solvents used were: water, ethanol (96%), ethanol-water (1:1), acetone (100%), acetone-water (1:1), methanol (100%), methanol-water (1:1), ethanol-methanol-acetone (1:1:1) and ethanol-methanol-acetone-water (1:1:1:1). The extraction was performed by refluxing at the boiling temperature of the solvent for 1 h and by process of maceration for 72 h. By spectrophotometric method (UV/VIS) high levels of total phenols, hydroxycinnamic acid, total flavonoids, and flavonols were determined. Regardless of the extraction procedure used, the highest mass fraction of total phenols (134.87 mg/g), hydroxycinnamic acids (66.08 mg/g) and flavonols (49.36 mg/g) was extracted with the ethanol-methanol-acetone-water solvent combination, while methanol showed best for flavonoids isolation. Based on the obtained results, it can be concluded that the better effect of extraction of polyphenolic compounds is achieved by adding water to the solvent than using a pure solvent